A diagnostic dilemma of a pulmonary nodule of a patient who suffered advanced ovarian cancer: A case report and a hypothesis

INTRODUCTION: This report presents a case of lung cancer which can be easily misdiagnosed as distant metastasis. Along with a literature review on the morphological, pathological and prognostic characteristics of lung cancer associated with cystic airspaces (LCCA), it would help to improve our understanding of the dynamic evolution of LCCA, to avoid its delayed diagnosis and treatment. We also propose here a hypothesis on the etiology of LCCA. CASE PRESENTATION: A patient with advanced ovarian cancer who presented with elevated serum CA125 at time of admission and had undergone TAHBSO at first, and second operation of sigmoid colon resection was performed due to her locoregional recurrence of ovarian cancer. After her second operation, patient showed further increment of serum CA125 and CECT scan indicated an airspace-related pulmonary nodule in the right middle lobe of her lungs. It was suspected that distant metastases of ovarian cancer had reoccurred postoperatively. CLINICAL DISCUSSION: After comparing the characteristic of metastatic ovarian cancer with LCCA, we diagnosed the pulmonary nodule as primary lung cancer. Surgery eventually confirmed the pulmonary nodule as second primary lung cancer associated with cystic airspaces. CONCLUSION: The rare occurrence of LCCA should merit special attention from clinicians and radiologists so as to avoid missed or delayed diagnosis. We propose here a hypothesis that LCCA is related to spreading of tumour cells during surgical procedures in lung cancer surgery. Should our hypothesis be substantiated in further studies, this would affect the operation procedures for surgeons in the future.